A Forgotten Practice Can Save US Industry $500B a Year

US engineering advancement has been catalyzed over the decades by external threats: the space-race threat from the Soviet Union in the 1960s; the economic threat from Japan's low-cost, high-quality manufacturing in the 1970s; the demographic threat from post-WWII engineering retirements in the 1980s; the global threat as US competitiveness declined in the 1990s; and now the environmental threat driving the need for global energy conservation and sustainability.

In addition, the aging and impending retirement of the baby-boom generation challenges the engineering profession, as these workers take with them a vast amount of knowledge and skill that must be replaced. One critical area, essential in manufacturing and transportation, is tribology, officially defined in 1966 as the science and technology of interacting surfaces in relative motion. Since an undergraduate engineering student receives less than one hour of instruction in tribology in a four-year program, this matter demands urgent attention.

Tribologists, through the development of air-bearing technology in the period between 1960 and 1980, made possible the extremely fast, reliable, precise, and accurate operation of the computer hard-disk-drive read/write head (approximately .05 inch x .04 inch x .01 inch) riding over the disk surface on a cushion of air at a height of 15 nanometers at an average speed of 53 mph. The challenge today for tribologists is to understand the variety of potential modes for wear and surface damage in an endless variety of mechanical systems, e.g., wind turbine components, such as the gearbox, which must last for 20 years without major downtime and costly repairs. Whether the goal is to reduce parasitic friction or enhance friction, the proper combination of geometry, materials, and lubrication must be employed in a design, i.e., a proper tribological approach, to ensure safety, performance, and energy-efficient operation. It has been estimated that the correct application of tribology throughout the US industry could save $500 billion annually.

Friction accounts for most of the energy consumed in our society, and friction is inevitably accompanied by wear. The object of lubrication is to reduce friction, wear, and heating of machine parts, which move relative to each other. A lubricant is any substance which, when inserted between moving surfaces, accomplishes these purposes. There are several types of lubrication: hydrodynamic refers to full-fluid-film lubrication, hydrostatic refers to lubricant introduced under pressure to create a full film, elastohydrodynamic refers to lubricant films between elastically deformable surfaces, boundary refers to a fluid film several molecular dimensions thick, and solid refers to solid lubricants used at high temperatures. Unlubricated surfaces have a friction coefficient about 1.0 with heavy wear, for boundary and thin-film lubrication the value is about .01 with slight wear, and for thick-film lubrication the value is about 0.001 with no wear.

The most common of all fluid-film bearings is the journal bearing, where a sleeve of bearing material is wrapped partially or completely around a rotating shaft to support a radial load. Shown is a plot of the coefficient of friction versus Hersey number (μN/P; μ = absolute viscosity in centipoise, N = shaft speed in rpm, and P = average pressure in psi) for a journal bearing under test conditions, and is a good measure of the state of health of the bearing.

There are other areas of science and technology in a similar state. Once this knowledge and skill is lost, getting it back will be near impossible.

Knowledge capturing has been a popular business topic ever since the Boomers hit their 50's. Probably has to do with hitting that stage in life that Ericson identified as wanting to pass on their knowledge and mentor individuals.
But the real question isn't capturing that knowledge. It's making it useful to those left behind. None of the Boomers went through old files from someone retiring in order to gain experience. We talked to them when they were there, but once they were gone we started fresh and made our own experience. Expecting more from the generation behind us now is just letting our egos get in the way. If they do things differently than we did, I'll bet it's a better solution than what we did in the past anyway.
It's like the downsizing in the past. Yes some things will be lost, but if it really was important it survives and grows. I guess those will be the Youtube clips with the most hits in the future....

Kevin. This is not a forgotten science. It, like many other Engineering disciplines, has become specialized. The STLE (Society Of Tribologists and Lubrication Engineers) had a website dedicated to this subject. STLE is the premier technical society serving the needs of more than 10,000 individuals and 150 companies and organizations that comprise the tribology and lubrication engineering business sector.

Engineering Schools should spend some time introducing the myriad of Societies available for their graduating classes.

When I graduated from college 37 years ago, my school had zero tribology classes that I was aware of. I agree, Kevin, that we need to hold onto this as an academic discipline. Seems to me the best place to start is in the schools -- practicing engineers tend to place high value on the knowledge they gained in engineering school. Schools (like mine) that didn't bother to offer those classes should be encouraged to explain why it's being neglected.

I also question the origin of the $500 billion number. It appears to have been plucked out of the low-friction airstream, I would guess.

In my Electrical engineering college days I don't recall much about friction except in a materials course and in statics. It was also discussed briefly in Physics.

But as a practicing engineer I was always aware of the need to assure that things did not wear, which meant always providing bearings of one form or another, since I never came up with a way to use the rollomite invention. ( I may have spelled it wrong). It always seemed intuitive to me that where surfaces were loaded against each other they had to either be anchored to each other or have a bearing of some sort. That is why bearing companies have catalogs full of useful information. I may possibly have spent a bit more than I had to on bearings at times, but the production machines that I designed never had wear-out problems. So perhaps it was money well spent.

While I do recognize the value of engineers having a "well rounded" education and the value of not wasting energy...

I find the statement - "It has been estimated that the correct application of tribology throughout the US industry could save $500 billion annually."... to be very flawed (and contradictory to demonstrating a well rounded education).

As important as the subject is.. any arguments stating it's importance with vague and un-sourced numbers just devalues the argument.

$500 billion? really? assuming we can make all frictional losses 5% better (less)? 50% better? 95% better? at what cost to implement? Who did this estimate?

78% of all statistics are made up on the spot... to support an idea of questionable importance (you get my point).

Temperature is an outsider in the laws of motion given by Newton and Einstein and this oversight is the source of the predictions of time-reversal-invariance made by these two great systems of motion. By taking into consideration Planck's law of blackbody radiation and the Doppler effect, in thinking about Maxwell's electromagnetic wave equation, I have shown that photons, in the environment through which any charged particle moves, act as a source of temperature-dependent friction on everything from elementary particles to galaxies. Because the optomechanical friction is universal and inevitable, no real systems are conservative, and temperature can no longer be an outsider in a fundamental and irreducible law of motion. I have defined the change of entropy in irreversible systems at constant temperature in terms of the optomechanical friction. The Second Law of Thermodynamics is explained by electromagnetic interactions between charged particles and the Doppler-shifted photons through which they move as opposed to chance and statistics. Consequently, the Second Law of Thermodynamics is shown to be a fundamental law rather than a statistical law. This result is consistent with intuition and the routine experience of engineers (and botanists).

Tribology - I do not remember hearing of this study in 27 years of product engineering or my 4 years of college. Of course I know the concept of friction wear and know to look for ways to avoid or minimize it depending on the application, but I never stopped to think that there was a discipline dedicated to this phenomenon.

It makes sense that there is an area of dedicated research and analysis for it, and considering how complex and varied friction generation and wear can be, the study must be equally complex. So it is somewhat distressing that as a field, I have never heard of it.

A discipline that it is not well publicized means few students can or will choose it as a pursuit. And with the "experts" retiring and no new blood replacing them, the knowledge base may disappear but we all know that the natural phenomenon will not.

One possibility is that as a society we will have to start learning the importance of this study again, not exactly from scratch, but from 10 steps back. The other possibility is that as a society being fed products created with planned obsolescence, the knowledge or expectation that products can have longevity will disappear.

Naperlou, you are right. Such topics have to introduce to schools and colleges and this will help them to understand the importance of such things from child hood days. Conservation of energy is a major factor and I think every has to be tuned for optimal usage and to minimize wastage.

I'm not sure that it's quite right to call tribology a "forgotten practice." Nanotribology in particular seems to be a hot topic for university research these days. That being said, traditional tribology doesn't get as much attention because it's no longer "sexy" (if rolling contact fatigue was ever sexy).

This is part of the disconnect between academia and industry; there are plenty of topics that have tremendous industrial significance, but seem to attract little academic interest. Conversely, there are issues that seem to attract lots of academic interest, despite having little industrial significance.

I think Northwestern University offers a couple of undergraduate-level tribology classes, which are taught by Dr. Q. Jane Wang. However, most universities don't do this. I certainly didn't take any tribology classes as an undergraduate.

Because of this, I often find myself relying on bearing manufacturers to fill in the gaps in my tribology knowledge. Most of the bearing manufacturers place a high priority on providing customers with engineering support. Koyo (Torrington) even has a mobile classroom that they will bring to your location.

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